Improvement in pneumatic pumps



UNiTnD STATES YHENRY GOTTFRIED,

PATENT OFFICE.

OF NEW YORK, N. Y.

IMPROVEMENT IN PNEUMATIC PUMPS'.

Specification forming part of Letters Patent No. 54,328, dated May 1, 1866.

` i I do hereby declare that the following'is a full,

clear, and exact description of the same, reference being had to the accompanying drawings, in which- Figure l represents an end view of a doubleacting air-pump constructed according to my improvements. Fig. 2 is a longitudinal centralvertical section of the same. Fig. 3 is alongitudinal vertical section of a single-acting air-pump with my improvements.

Similar letters of reference indicate corresponding parts in the several figures.

The object of my invention is to obviate the usual great loss of effective working of airpumps, caused by having aclearance left, when the piston is at the end of its stroke, between it and the respective cylinder-head, in order to prevent the same from coming in contact and breaking each other. rlhe usual amount of this clearance is sufficient room that the air compressed therein, which, by the return of the piston, will take up a room nearly equal to one-third f the acting contents of the cylinder, and therefore the piston is not able to suck while moving on the irst third of its stroke.

N ow, this'invention consists, first, in the employment of a secondary piston or yielding cylinder-head, instead of only one fixed cylinderhead, to air-pumps, which is held to its place byastrong spring and arranged with the stroke of the piston, that the same piston shall completely close upon the said yielding cylinderhead and allow no air to remain between, and that the said cylinder-head shall yield after the air is expelled and prevent the breaking ofthe piston or said head by coming in contact with each other.

It consists, second, in the employment of an air-chamber arranged in the end of the cylinder and in the rear of the said yielding head and connected with the discharge or reservoir of the pump, whereby said yielding head is provided with a selfregulating sufficientlystrong spring to withstand the pressure from the piston in order to expel the air at every stroke between it and the said piston, while at the same time to allow the cylinder-head to yield when the piston has come in contact with it.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

C, Fig. 3, and C' C', Figs. l and 2, represent the oylinders'of a single-acting and a doubleacting pump, which are made with water-jackets B, Fig. 3, and B', Figs. l and 2, surrounding the same, for the purpose of cooling the respective cylinders while in action.

I, Fig. 3, represents the piston of a singleacting, and P', Fig. 2, of a double-actin g, pump, which are properly packed to work air-tight in their respective cylinders.

The suction-valve h of the sin gle-acting pump is arranged in the piston, whereas the suctionvalves h' h' of the double-acting pump are located in the cylinder.

The delivery-valve a of the single-acting pump is arranged in the yielding head M, hereinafter described, whereas the delivery-valves n' n' of double-acting pump are arranged in the cylinder C' opposite to the suction-valves h' h' of the same, in the ordinary way.

t, Fig. 3, and t t', Fig. 2, represent the respective discharge-pipes or reservoirs of the single and double acting pumps.

N 0W, the one end ofthe cylinder of the singleacting pump and both ends of the cylinder C' of the double-acting pump are provided with extensions beyond the stroke of piston, which are bored a little larger than the bore of the cylinder, (clearly shown in Figs. 2 and 3,) forming a shoulder, A or A' A', atvthe end of the stroke of the pistons 5 and in place of the usual cylinder head or heads, a little off from the end of the stroke of the piston, I place close upon the end of stroke of piston yielding heads M' M', Fig. 2, or a yielding head, M, Fig. 3, made to slide air-tight in the aforesaid extensions of the respective cylinders, and then I place the usual lixed cylinder-heads H or H' H' on the final end of the extensions or cylinders, thereby leaving a certain chamber, S, Fig. 3, or chambers S' S', Fig. 2, between the yielding head M, Fig. 3, or heads M' M', Fig. 2, and the actual or xed cylinder-heads H or H' H', in which said yielding heads M' M' or head M are or is allowed to slide to or from their respective pistons. The rear part of the said yielding heads M or M' M' are made with projecting stems, which are itted to work in corresponding recesses p' p" or in an opening, 19"', in the xed cylinder-heads, to form a more perfect guide to the said yielding heads, which projection of the yielding head, if used in a single-actin g pump, as shown in Fig. 3,is made of tubular form, and` is Working through the cylinder-head H, properly packed air-tight.

g' g', Fig. 2, and q, Fig. 3, are passages, or is a passage from the discharge-pipes t t', Fig. 2, and discharge-pipe t, Fig. 3, to the air-chambers S' S', Fig. 2, or air-chamber S, Fig. 3, in each of which is located a drop-valve, r, which opens, by a pressure from the respective discharge-pipe, toward the respective air-chamber S or S', but closes air-tight by a pressure in reverse direction. I

The aforesaid yielding heads, when held to the respective shoulders A A', Fig. 2, or A, Fig. 3, are made to leave no room for clearance between their respective faces and respective faces oi' pistons when at the end of stroke.

By having the delivery-valve n of the singleacting pump arranged in the yielding head the recess occurring from the construction of the delivery-valve is readily lled up by having a corresponding projection on the end of the piston. (Clearly shown in Fig. 3.) y

From the foregoing the operation of the single or double acting pump may be clearly per-.j ceived. When the pump is in action the yield-y ing heads are, or head is, to a certain extent,-i prevented from yielding by means of the press.l ure of the air in its rear, the same having eu-A tered through the respective drop-valve r, and constantly balancing its pressure with the pressure in the discharge-pipe or reservoir, and the air and its quantity between the rear of said heads M' M' or head M cut off from thev respective drop-valve r, and, being small in proportion to the air and its quantity in the reservoir, is able to withstand a higher pressure from the piston, on account of being less elastic, and on account of the area of the face of the yielding heads exposed to the piston being less than the area exposed -to the said air chamber or chambers than the air. in the reservoir or discharge pipe. Consequently when the piston is forced upto the yielding head the air between is completely discharged into the discharge-pipe or reservoir at every stroke and complete fresh supply drawn into the cylinder by the return motion of the piston, and is only subject to not avoidable leakages in producing air-tight joints, while at the same'time the said headM or heads M M' are enabled to yield when the piston strikes the heads, and are guarded against breaking one another.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The employment ot' a yielding head, M, or heads M' M', arranged in the cylinder of airpumps in a manner to co-operate with the main piston, for the purpose herein shown and described.

, 2. The employment aud arrangement of the air-chamber S and passage q tothe reservoir or discharge pipe, in combination with the yielding head M, the whole operatin g, and for the purpose herein shown and described.

3. The combination and arrangement of the drop-valve r in the passage q, and with the yielding head M, operating in the manner and for the purpose herein described.

4. The employment of the delivery-valve fn., arranged in the yielding head M, for the purpose oi' simplifying the construction in producing an air-tight joint between the yielding head and piston when brought together.

HENRY GOTTFRIED.

Witnesses:

M. M. LIVINGSTON, R. BOEKLEN. 

